是的,我知道有AlertDialog。但我很惊讶地知道在Android中显示对话框有多么困难(好吧,至少不是程序员友好的)。

我曾经是一名。net开发人员,我想知道在android上是否有类似的功能?

if (MessageBox.Show("Sure?", "", MessageBoxButtons.YesNo) == DialogResult.Yes){
    // Do something...
}

当前回答

史蒂夫的回答是正确的,尽管有些片段过时了。下面是一个FragmentDialog的例子。

类:

public class SomeDialog extends DialogFragment {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return new AlertDialog.Builder(getActivity())
            .setTitle("Title")
            .setMessage("Sure you wanna do this!")
            .setNegativeButton(android.R.string.no, new OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // do nothing (will close dialog)
                }
            })
            .setPositiveButton(android.R.string.yes,  new OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // do something
                }
            })
            .create();
    }
}

开始对话:

            FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
            // Create and show the dialog.
            SomeDialog newFragment = new SomeDialog ();
            newFragment.show(ft, "dialog");

您还可以让类实现onClickListener,并使用它来代替嵌入式侦听器。

其他回答

你可以为决策实现一个通用的解决方案,并在另一种情况下使用,而不仅仅是yes/no和自定义警报动画或布局:

像这样的东西;首先创建用于传输数据的类:

public class AlertDecision {

    private String question = "";
    private String strNegative = "";
    private String strPositive = "";

    public AlertDecision question(@NonNull String question) {
        this.question = question;
        return this;
    }

    public AlertDecision ansPositive(@NonNull String strPositive) {
        this.strPositive = strPositive;
        return this;
    }

    public AlertDecision ansNegative(@NonNull String strNegative) {
        this.strNegative = strNegative;
        return this;
    }

    public String getQuestion() {
        return question;
    }

    public String getAnswerNegative() {
        return strNegative;
    }

    public String getAnswerPositive() {
        return strPositive;
    }
}

后的接口,用于返回结果

public interface OnAlertDecisionClickListener {

    /**
     * Interface definition for a callback to be invoked when a view is clicked.
     *
     * @param dialog the dialog that was clicked
     * @param object The object in the position of the view
     */
    void onPositiveDecisionClick(DialogInterface dialog, Object object);
    void onNegativeDecisionClick(DialogInterface dialog, Object object);
}

现在你可以很容易地创建一个utils(在这个类中,你可以为警报实现不同的动画或自定义布局):

public class AlertViewUtils {

    public static void showAlertDecision(Context context,
                                         @NonNull AlertDecision decision,
                                         final OnAlertDecisionClickListener listener,
                                         final Object object) {

        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setMessage(decision.getQuestion());
        builder.setPositiveButton(decision.getAnswerPositive(),
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        listener.onPositiveDecisionClick(dialog, object);
                    }
                });

        builder.setNegativeButton(decision.getAnswerNegative(),
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        listener.onNegativeDecisionClick(dialog, object);
                    }
                });

        android.support.v7.app.AlertDialog dialog = builder.create();
        dialog.show();
    }
}

最后是活动或片段的召唤;你可以在你的案例或其他任务中使用这个:

public class MainActivity extends AppCompatActivity {

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity);
        initResources();
    }

    public void initResources() {
        Button doSomething = (Button) findViewById(R.id.btn);
        doSomething.setOnClickListener(getDecisionListener());
    }

    private View.OnClickListener getDecisionListener() {
        return new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDecision decision = new AlertDecision()
                        .question("question ...")
                        .ansNegative("negative action...")
                        .ansPositive("positive action... ");
                AlertViewUtils.showAlertDecision(MainActivity.this,
                        decision, getOnDecisionListener(), v);
            }
        };
    }

    private OnAlertDecisionClickListener getOnDecisionListener() {
        return new OnAlertDecisionClickListener() {
            @Override
            public void onPositiveDecisionClick(DialogInterface dialog, Object object) {

                //do something like create, show views, etc...
            }

            @Override
            public void onNegativeDecisionClick(DialogInterface dialog, Object object) {
                //do something like delete, close session, etc ...
            }
        };
    }
} 

你可以在Kotlin中轻松完成:

 alert("Testing alerts") {
    title = "Alert"
    yesButton { toast("Yess!!!") }
    noButton { }
}.show()

AlertDialog。Builder真的没有那么难用。一开始肯定有点吓人,但一旦你使用了一点,它就变得简单而强大了。我知道你说过你知道如何使用它,但这里只是一个简单的例子:

DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        switch (which){
        case DialogInterface.BUTTON_POSITIVE:
            //Yes button clicked
            break;

        case DialogInterface.BUTTON_NEGATIVE:
            //No button clicked
            break;
        }
    }
};

AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setMessage("Are you sure?").setPositiveButton("Yes", dialogClickListener)
    .setNegativeButton("No", dialogClickListener).show();

你也可以重用那个DialogInterface。OnClickListener如果你有其他是/否框,应该做同样的事情。

如果你是从视图中创建对话框。OnClickListener,你可以使用view.getContext()来获取Context。或者你也可以使用yourFragmentName.getActivity()。

Steve H的回答是正确的,但这里有更多的信息:对话框之所以以这种方式工作,是因为Android中的对话框是异步的(当对话框显示时,执行不会停止)。因此,您必须使用回调来处理用户的选择。

在关于Android和。net的区别(因为它涉及到对话框)的更长的讨论中,看看这个问题: 对话框/ alertdialog:如何在对话框启动时“阻止执行”(. net风格)

Kotlin在Android::

    override fun onBackPressed() {
        confirmToCancel()
    }

    private fun confirmToCancel() {
        AlertDialog.Builder(this)
            .setTitle("Title")
            .setMessage("Do you want to cancel?")
            .setCancelable(false)
            .setPositiveButton("Yes") {
                dialog: DialogInterface, _: Int ->
                dialog.dismiss()
                // for sending data to previous activity use
                // setResult(response code, data)
                finish()
            }
            .setNegativeButton("No") {
                dialog: DialogInterface, _: Int ->
                dialog.dismiss()
            }
            .show()
    }